Silylalkyl esters of phosphorus are not new. There are many such materials reported in the chemical literature and their preparations are described in patents and chemical journals.
Such preparative methods are essentially inadequate for the full scale commercial production of these esters as the methods generally result in low yields and uneconomical energy consumption.
For example, one method is described for preparing such esters by the addition of (C.sub.2 H.sub.5 O).sub.3 SiH to unsaturated phosphites e.g. ##STR1##
This work was reported by E. F. Petukhova et al. Zh. Obsch. Khim., 1970, 40,(3); 606 CA 73 25569 (1970), and the best yield was 47.4%.
Chloromethylsilanes reacted with sodium diethylthiophosphate was reported to give thiophosphate esters according to the scheme ##STR2## Again, yields were low and the scheme requires the removal of the NaCl solids. [F. Feher and A. Blumke, Ber 90 No. 9 1934 (1957)].
Further, Hewins, et al. has disclosed the preparation of silyl phosphorus esters in C.A. 71, 102318t, from the reaction of ##STR3##
In an early patent, U.S. Pat. No. 2,612,514, Plueddemann disclosed the preparation of higher organic esters of relatively strong acids using amine catalysts. Such reactions did not involve silicon compounds nor were the yields more than moderate.
The above mentioned patent does not disclose or make obvious the instant invention in view of the fact that those skilled in the art would not expect that a haloalkylsilane would react with the methyl ester of phosphorus with such speed and without materially affecting the labile groups on silicon. It is believed that the silicon atom of the haloalkyl or haloaryl silane activates the halogen atom and thereby causes the faster reaction.
It has now been demonstrated that silylalkyl esters of phosphorus can be prepared quickly and in greater yields than has previously been possible.